Editor's note: This story has been updated to add that Timucuan Ecological and Historic Preserve has closed due to the storm.

Hurricane Matthew was expected to strengthen into a category 4 hurricane by the time it reaches Florida, leading many units of the National Park System from Florida into North Carolina to batten down for the storm.

Among the park units closed on Thursday were Everglades, Biscayne, Canaveral National Seashore, Cumberland Island National Seashore, Big Cypress National Preserve, Timucuan Ecological and Historic Preserve, Cape Lookout National Seashore, Castillo de San Marcos National Monument, Fort Matanzas National Monument, Fort Sumter National Monument, and much of Cape Hatteras National Seashore, where the Oregon Inlet, Cape Point, and Frisco campgrounds were operating on a one-day availability basis.

Visitor services on Hatteras Island and Bodie Island at Cape Hatteras, and at Fort Raleigh National Historic Site and Wright Brothers National Memorial, were open Thursday.

Congaree National Park in central South Carolina was to close Friday at noon, and its Longleaf and Bluff campgrounds closed Thursday morning. Moores Creek National Battlefield in North Carolina planned to close Friday-Monday.

"Hurricane conditions are expected to first reach the hurricane warning area in Florida by late today and will spread northward within the warning area through Friday. Tropical storm conditions are first expected in Florida by late this morning," the National Hurricane Center forecast Thursday morning. "Hurricane conditions are possible in the hurricane watch area in northeast Georgia and South Carolina by early Saturday, with tropical storm conditions possible on Friday night. Tropical storm conditions are possible in the tropical storm watch area on the Florida Gulf Coast beginning later today."